الفهرس 
TitleOnly 14 pages are availabe for public view
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Abstract
Urinary tract infections (UTI) are one of the most common infections in humans. Uropathogenic Escherichia coli (UPEC) are the most common bacteria causing uncomplicated UTIs.
UPEC possess a diverse array of virulence and fitness factors.Though the etiology of UTI is not clearly understood, it has been stated that the various virulence –associated characteristics might be contributing to infectivity independently or together
Moreover, certain serotypes of E. coli are consistently associated with uropathogenicity and are designated as uropathogenic E.coli (UPEC)
Such UPEC harbors virulence properties which are usually absent in non-pathogenic E. coli.
The aim of the present study was the detection f virulence factors as well as biofilm formation and the antibiotic resistance profile of E. coli isolated from urine and stool of patients with recurrent UTIs and E coli isolated from stool of healthy individuals in order to determine the factors which are associated with recurrent UTIs
Forty strains of E.coli isolated from urine and stool samples of patients (16 females and 4 males) with recurrent UTI admitted to the Microbiology Department of Medical Research Institute, Alexandria University and twenty strains of E.coli isolated from stool of healthy individuals (10 females and 10 males) were included in this study.
The strains were identified and biochemically confirmed as E.coli by conventional methods and subjected to the following:
1. Serotyping, using polyvalent and monovalent antisera for the typing of E.coli group O and H antigens by agglutination method
2. Antibiotic sensitivity by Kirby Bauer disc diffusion method.
3. Determination of the phenotypic resistance pattern to the beta lactam antibiotics by Modified Double Disc Test (MDDST) for the ESBL production, Modified CLSI ESBL confirmatory test and Modified Hodge test(MHT).
4. Biofilm formation by Congo-red agar method
5. Detection of uropathogenic virulence genes by polymerase chain reaction (PCR)
The O serogroups usually associated with UPEC were found in 7(35%) of strains isolated from urine of UTI patients,or from stool of UTI patients versus 3(15%) of strains isolated from stool of healthy individuals
Only 2(10%) of the strains isolated from urine of UTI patients, could not be assigned to a serogroup compared to 5(25%) of strains isolated from stool of healthy individuals.
O25 was detected in 5 (25%) of the strains isolated from urine of UTI patients,7 (35%) of the strains isolated from stool of UTI patients, and 2(10%) of the stool of healthy individuals, while O18 and O78 were detected in 1(5%) of the strains isolated from urine of UTI patients.O20 was found in one strain (5 %) isolated from the stool of a healthy individual.
Summary
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The most common serogroup was O25 detected in 5(25%) of the strains isolated from urine of UTI patients, while O18, O44, O63and O78 were detected in 5% of the strains. On the other hand, 7(35%) of strains isolated from stool of UTI patients were of serogroup O63,7(35%) of serogroup O25 compared to 2(10%) of serogroup O 25and 1(5%) of serogroups O63 of strains isolated from stool of healthy individuals.
Two strains of diarrhegenic E. coli belonging to serogroup O157 H7 (Enterohemorrhagic E.coli) and O44 H7 (Enteroaggregative E.coli) were isolated from the urine but not the stool of a UTI patient.
60% of the positive biofilm producers of E coli isolated from urine of UTI patients were MDR compared to only 20% of the negative biofilm producers.
Biofilm and FyuA were correlated in 75% of the E coli isolated from urine (an iron-poor environment) compared to 60% of E coli isolated from stool of UTI and 55%of E coli isolated from stool of healthy individuals.
Usp was detected in 70% of E.coli isolated from urine of UTI patients compared to 45% and 5% of E coli isolated from stool of UTI patients and healthy individuals respectively this was not statistically significant.
HlyA and cnf-1 genes were not detected in any of our 60 E. coli isolated from urine or stool of UTI patients or of stool of healthy individuals.
fim H was detected in 19(95%) of E.coli strains causing urinary tract infection but also in 14-20 (70-100%) of E.coli isolated from stool of patients with UTI or of healthy individuals.
Pap and afa genes were detected in 35% of E. coli isolated from urine of patients with UTI versus 15% and 45% in E.coli isolated from stool of UTI patients respectively
On the other hand, pap and afa genes were not detected in E.coli isolated from stool of healthy individuals.
The detection of ESBL alone among E. coli isolated from urine of UTI patients was 8 (40%) out of the 20 isolates while another 4(20%) strains co-produced AmpC
ESBL were also detected alone among E coli isolated from stool of UTI patients in 8 (40%) out of the 20 isolates while another 2(10%) strains co-produced AmpC. Similarly ESBL were also detected alone among E. coli isolated from stool of healthy individuals in 8 (40%) out of the 20 isolates while another 2(10%) strains co-produced AmpC.
Metallobeta-lactamases were detected in 1(5%) E.coli strain isolated from urine of UTI patients and 2(10%)E. coli strains isolated from stool of UTI patients and 1(5%)E coli strain isolated from stool of healthy individuals.
2(10%) of the E coli isolated from urine and stool of UTI patients produced carbapenemases compared to 1 (5%) of the E.coli isolated from healthy individuals.
No statistical significance was found between the incidence of ESBL, AmpC, and carbapenemases among E.coli isolated from urine and stool of UTI patients or from stool of healthy individuals,
Summary
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90 % of E. coli isolated from UTI patients were sensitive to Imipenem while sensitivity to aminoglycosides ranged from100% to amikacin, to 65% to gentamicin and 40% to tobramycin.
Among the 20 uropathogenic E. coli 11 (55%) isolates were MDR, of which 8 (72.7%) were ESBL producers. On the other hand, among the 12 ESBL producers 8 (66.6%) were MDR.
Among E.coli isolated from stool of UTI patients 13( 65%) isolates were MDR, of which 8 (61.5%) were ESBL producers. On the other hand, among the10 ESBL producers 8 (80%) were MDR. E coli isolated from urine and stool of UTI patients.
MDR and or ESBL producers had different antibiograms indicating the presence of different strains in urine and stool of UTI patients. 50% of E coli isolated from the stool of healthy individuals were ESBL producers and 80% were MDR.
Their presence increases the risk of transmission to other individuals as a result of human to human transmission or through the environment.